Control mechanism for sewing machines



D. BESWICK CONTROL MECHANISM FOR SEWING MACHINES March z5, 1930.

Filed Jan. 19, 192'? Patented Mar. 25, 1930 UNITED STATES DAvID BESWICK, F BROOKLYN, NEW YORK CONTROL MECHANISIVI FOB SEWING MACHINES Application led January .19, 1927. Serial No. 162,138.

rlhis invention relates to control mechanisms for sewing machines and more particularly to knee operated devices for controlling the speed of electrically driven sewing machines.

It is a general object of the present invention to provide a novel and improved form of knee control mechanism for sewing machines.

More particularly it is an object of the present invention to provide a novel mechanism adapted to clamp a portable sewing machine to a table or a like supporting surface and to provide means whereby a control button or lever on the machine may be actuated by the knee.

A further object of the invention consists in the provision of a device adapted to interlock with the base of a sewing machine and having a lever system adapted to cooperate at one end with a control button on the machine base and at the other end to be actuated by the knee, means being provided to attach the mechanism to a table or other supporting means whereby the machine is prevented from movement by pressure on the actuating device.

Other and further objects of the invention will be more apparent to those skilled in the 3o art upon a careful consideration of the accompanying drawings and following speciiication, wherein is disclosed a single exemplary embodiment of the present invention with the understanding, however, that such e5 changes may be made therein as fall within the scope of the appended claims without departing from the spirit of the invention.

In said drawings:

Figure 1 is a side eleva-tion of a portion of e@ a table top showing the operating mechanism of the present invention attached thereto, a portion of a portable sewing machine being disclosed in elevation therein;

Figure 2 is an end elevation of the parts 4.5 shown in Figure 1;

Figure 3 is a partial plan view thereof; and

Figure 4L is a vertical central section thru the operating mechanism taken on line of Figure 2.

In the applicants copending application Serial No. 19,726, led March 31, 1926, for electric driven portable sewing machine, is disclosed a portable sewing machine having a base which is hollow and encloses the rheostat for controlling the speed of the motor used for driving the machine. An operating button projects thru the front edge of the base where it may be conveniently manipulated by the thumb while sewing. There is also disclosed in that application mechanism whereby the button may be operated by a foot treadle. rllhe present invention contemplates the provision of means for operating such a control button by the knee.

Referring to the drawing there is disclosed at 10 the base of a sewing machine which is hollow and contains a rheostat (not shown) adapted to be operated to regulate the speed of the driving motor 11 by means of the control button 12 projecting thru the front face or edge 13 of the base. The button is adapted for reciprocation to control the speed of the motor which drives the fly wheel 14 by means of an internal friction disk, not shown.

The sewing machine, including the motor which is mounted on an extension of the base 10, is shown as supported on a table or other suitable support such as 15. The knee control mechanism forming the object of the present invention, is indicated generally by the reference character 16 and is adapted to cooperate with the control button l2. It is clamped over the front edge of the table 15 and has a plate 17 which may be adjustably positioned in respect to the floor in order that the operators knee may conveniently be placed beneath the plate so that by lifting the heel the knee may be raised to raise the plate and, by means of the mechanism to be later described, regulate the position of the control button 12.

Since the pressure on the button is in a direction parallel to the surface of the table it is seen that the sewing machine, being quite light, must be secured against movement away from the edge of the table. This is secured by clamping the machine to the table by means on the knee control mechanism.

The base of the machine is provided with two forwardly projecting bosses 18 which lie with their bottoms against the table surface and are perforated vertically as shown at 19. A casting 2O of substantial T-shape in plan has the head 21 thereof provided with the wings 22 adapted to rest on top of the bosses 19. Each wingis provided with a. depending pin 23 adapted to. pass into the corresponding opening 19 in the boss. These pins may conveniently Ybe the lower ends of screws passed thru the wings. Thevtail of the is enlarged as at 24 to provide a circular portion perforated vertically as at 25andadapted tc receive therein the tube 26. This tube may have a pressed lit into the portion 24' so that itsend is just flush with the top of this por` tion. Thelower part of the tube 26 is eX- ternally threadedas shown at 27.

[i lowerclamp member 28 is providedwith the sleeve 29 adapted to have a loo-se sliding lit over the tube 26. A suitably splined connection` 30 prevents rotation of the sleeve. On the end of the member 28 is a clamping pad- 31 directly beneath the head 21 of theT. A wing nut 32 is threaded. onto the tube 26 and is adapted to engage the bottom of 4the sleeve 29 so` 'that the pad 31 can be clamped againstA the bottom surface of the table, drawing down the wings 22 onto the bosses 18 and Y securely holding the machinebase to the table in order. that it may notv slide when the button is pressed. Between the wings 22 the head portion 21 extends substantially down to the table top as shown at 33 in order to prevent clamping the machine so tightly that the bosses are drawn into the material of the table top and the rear of the machine thus elevated.

Pivoted to the screw 34, the lower end of which forms one ofthe pins 23, is the button controlling lever 35 which may conveniently have the tapered shape shown in Figure 3. 1t extends from the screw 34 over the'end of the button 12 as best shown in Figures 1 and 3. lt will'beeseenthat movement of the vlever toward the ymachine basewill cause the button to be pressed inwardly. Such movement of the lever` is effectedby the cranked lever 36 pivoted at 37 in a slot in the part 21, the end of the cranked lever partially fitting within the slot. The curved face 33 of this lever engages against thefront edge of the lever 35. It will be seen that raising the outer end 39- of the lever 36 will cause the inclined face 38 toA press against the front face of the lever 35 andthus cause inward movement of the button 12.. The outer end39 of the cranlredlever is adapted to be Vraisedby engagement with the head. 4t() ofthe control tubev 41Y which fits with a. snugI sliding fit 'j within thek tube 26, the head resting onthe end of the tube 26 andthe enlargement 24. TheA tube .l1 eXtendsa considerable distance vbelow the end 'ofthe tube 26 as bestshownin Figure 1 and is surrounded byy an open coiledspring l2 which bears at its upper endagainst.l the lower end of the tube 26 and at its lower end against the ferrule 43 secured to the tube al1 in any suitable manner.

rlhe knee plate 17 is attached to a rod de which has a sliding l'it within the tube al1. lt may be secure-d in any desired adjusted position according to the height of the operators linee from the floor by means of the thumb screw l5 threaded thru the ferrule 43 and the tube ll1 and having its end bearing against the rod del'. ht .will thus be seen from thc constructions described that an upward movement of the lineev plate 17 will impart a similar movement to the head 40 of the tube ell which will'lift the end 39 of the cranked lever 36, which will cause the inclined face 33 of this lever to vbear against the front edge of the lever 35 causing the end ofthe sameto move inwardly and press the 4button 12 in the same direction. The rheostat is so arranged that this inwardmovement of the button gradually` eliminates resistance fromthefmotor circuit.

lt will be seen that the linee control mechanism performs two functions, i. e., it first securely clamps and positions the sewing machine in relation to the edge ofthe table and holds itV against movement and second, it provides means whereby motion of the knee in avertical direction may be readily controlled, transmitted and reduced in quantity to the button 12 whereby af minute control of the speed of the motor may be obtained; The device is readily attached and detached by the mere actuation of the wing nut 32 and, `being small in size, is easily portable and can be clampedV in the carrying. case of the machine. Themost valuable features of the device isthat it does not require any special form ofV rheostat to be designed for it, itbeing adaptable to control the speed of any machine having a button which is L-intended vfor manual control at times. The operating device is self contained, having its own return spring. Vlt is adjustable inheight fromthe floor to suit all ordinary sized persons,` and its operation in practice has been found extremely satisfactory.

Having thus described the invention, what is claimed as new and desired-to be secured by Letterslatent is:

1. The combination with a sewing machine having a push button projecting therefrom, anda support for said machine of an oper ating mechanism for said push button clamped to said machine, and to said support.

2. The combination with a. sewing-machine having. a, push button projecting therefrom, and a separate support forsaid machine, of anoperating mechanism for said push button and means on said mechanism to clamp said machine tosaid support;

3.y The combination with aportable sewing machine having a horizontally movable ing machine having a horizontally movable push button projecting therefrom, and a separate horizontal support for said machine, ofmeans for converting vertical motion to horizontal motion to operate said push button, said means being removably clamped to said support.

5. The combination with a sewing machine having a horizontally movable push button projecting from the base thereof, and a horizontal support on which said machine rests, of means for converting vertical motion to a horizontal motion to operate said push button, said means being interconnected with said machine and said support to prevent relative horizontal movement.

6. In combination with a sewing machine having a base with a button projecting therefrom, of a clamp adapted to secure said base to a support, a member slidable in said clamp and adapted to be moved by the knee of an operator and means whereby the movement of said member is transmitted to said button.

7. In combination with a sewing machine having a base with a button projecting therefrom, of a clamp adapted to secure said base to a support, a member slidable in said clamp and adapted to be moved by the knee of an operator, a lever pivoted to said clamp and having one end in engagement with said button and means connecting said lever and member for movement in unison.

8. In a knee control for sewing machines, in combination, a member adapted to be supported adjacent a machine, a tube depending therefrom, a second tube slidable in said irst tube and having an end above said member, a knee plate associated with said second tube, a cranked lever having one end pivoted to said member and the other end resting on said end, a second lever pivoted to said member'in a plane at right angles to that of the first lever, a portion of said first lever being adapted to bear on said second lever for the purpose described.

9. In a knee control for sewing machines, in combination, a member adapted to interlock with the base of a sewing machine, a tube depending therefrom, a clamp arm slidable on said tube, a second tube slidable within said lirst tube, a knee plate secured to said second tube, an end on said second tube above said member, a cranked lever having one end pivoted to said member and the other end resting on said end and a second lever pivoted to said member and adapted to be engaged by said first lever for the purpose described.

In testimony whereof I hereunto aiiix my signature.

DAVID BESWICK. 

